Grinding machine



J. BATH GRINDING MACHINE May 6, 1930.

2 Sheets-Sheet 1 Filed April 4, 1927 J. BATH GRINDING MACHINE May 6, 1930.

Filed April 4, 1927' 2 Sheets-Sheet 2 Jew 20 Fig. 2 is an end elevation of the machi Patented May 6, 1930 UNITED STATES JOHN BATH, or wonons'rnn, MASSACHUSETTS Gnmnine Application filed April-4,

This invention relates to "a grinding machine adapted for general'purposes but par- 'ticularly designed for the grinding of screw threads in taps and for grinding other '5 threaded work. r

It is the general object of my invention to provide improvements in the construction and arrangement of parts in such a machine, by which improvementsthe wear of certain parts may, be reduced, the removal and .re-

placement of parts may be facilitated, and the general operation of the machine may be made more reliable and satisfactory.

A preferred form of the invention is shown in the drawings inwhich F'g. 1 is a partial plan view of the head end of a thread grinding machine; v v

Figs. 1" and 1 are detail plan views of oer-- k t-ain parts shown in Fig. 1;

looking in the direction of the arrow 2- in Fig.1; V V 1 Fig.3 is an enlargedsectional elevation, taken along the line 33'in Fig. 1;

Fig. 4 is a transverse sectional view along the line 44 in Fig. 3; and I Fig.5 is an enlarged detail plan view of certain parts to be described. I

'Referring to thedrawings, I have-shown portions of a thread grinding machine com-t prising a base 10 having a wheel table 11 slidably mounted on guide-ways 12 and 13 formed on the rear'portion of the base 10. A. cross slide 14 is mounted on the wheel table 11 and supports the grinding wheel Mechanism for rotating the work is mounted in a head 15, supported on the front portion of the frame 10. A'worm 16 (Fig. 1) is mounted on a worm shaft 17 and is rotated in any convenient manner, as by a belt 18 (Fig. 2) running over a pulley 18. The worm 16 engages a worm wheel 19 (Fig. 1) which is connected by bevel gears 20 and 21 to a pair of sliding change gears 22 and 23.. These gears mesh selectively with change gears 24 and 25 on adrive shaft 26.

The head center 27. and face plate 28 by which the work is supported and rotated are mounted on a separate drivingmember 30 which is aligned 'with the drive shaft 26 but.

, taken ne, v

Macrame- 1927. Serial no. 180,741.

is provided with entirely separate bearings.

Power is transmitted from the shaft 26 to the member 30 byspiral gears 31,' 32, 33 and 34 (Fig. 1 the gear '31 being on the drive shaft 26, the gears 32 and 33 being on an intermediate shaft 35, and the gear 34 being on the driving member 30.

I will now describe the driving connections between the drive shaft 26 and the wheel table 11, said connections forming an important part of my present invention. For this con- 'necting mechanism I provide a bracket '40 (Fig. 1), boltedto the end of the base 10 and projecting longitudinally a substantial distance beyond the .end'of thebase. In this bracket an outer bearingisprovided for the drive shaft 26, which extends through the bracket and has a driving gear 41 secured to its outer end. r

A" series of change gears 42, 43;44 and 45 are mountedon a supporting plate 47 which lssecured to the bracket 40,by bolts 48, extending through arcuate slots "concentric with a gear-49 which is aligned'with a lead screw 5O-(Fig. 1)" by which the wheel table 11 is reciprocated. The" plate 47 is centered on the axis of the gear 49 and lead screw 50 by a flange 52 (Fig. 3), extending into a circular opening; or recess 54 in the bracket 40. The change gear plate 47' may thus be swung. abouttheaxis of'the gear'49 to cause the uppermost change gear 42 tosuitablyengage the driving gear 41 andmay be secured in such adjusted position.

r The gear 49 is secured to the outerend of a short shaft 55, rotatable in abearing hub 56 which is secured by bolts'57 to the inner face of the'bracket 40 and which is provided with a projection 58 bywhich the hub is centered in the opening 54 previously described. The short shaft is provided with a flanged inner end 60, which engages the inner end of the hub 56; A collar 61 is keyed to the shaft 55 and is'longitudinally adjustable by a nut 62 threaded on said shaft. A binding screw 63 is also provided for retaining the adjust-' ment of the nut 62. By suitably adjusting the sliding collar 61 with respect to the projection'58,-. any end play of the short shaft 55 may beeliminated- 4 The lead screw 50 for the wheel table 11 is I provided with an extension 65 (Fig. 3) fitting the edge of the flangefifl; th-astpretentin irela tive angular movement of the parts 60 and67.

' By removing the bolt 68, however,='-theiparts i to may be easily separated. V c The nut for the lead' screw50comprises two threaded portions and- 74,imoun ted in thebearing-portiod 75 of ;anut bracket- 76. Both nut portions 73 and-T4: areikeyed in the bearing portion-I75 of the bracket 7 6,-as' indicated at 7 'Z in Fig; 4a.; The nut portion 7 3-is forced. into; the bracket portion '75 i and is intended to remain fixed therein The nut portion 'l' l, howeverfls provided-withathreaded outer; extension; on which an adj ustingnut '78 is mounted. 3 By slightly turning the nut 78, the nut portion 745 may be drawn outward in the bracketportion 75, and by such slight longitudinal adjustment, any wear between the nut; and the lead screwmay' be taken up. ;The' bracket 7 6 is'secured-by bolts 80 Fig. I) to a verticalbeafring face 81, formed on the side of-arecess 82 in the wheel tablev 11.; A removablecap plate 83 o'rdinarily covers the recess 82, but may be removed togive access to. the bolts 802' One end ofthezrecess 82 is cut awa y; as indicated in- Fig. 1-,and isfipro- ,v ided! with; a filler piece 85- held' in position byabolt86. .A- guard plate 87 (Fig. 4-) is mounted-on the-base- 10and extends between the wheel table 11 and the bearing'bracket 76 in every position'of thewheel table, thus effecti-ve'lygprotecting the'lead screw from dirt and abrasive.

avingdescribed thefdetail's-o'f construction of my improved grinding machine, the

use andadvantages-thereof will be readily understood. ln theifirst place the' provision of the longitudinally projecting bracket 40 removes the change gears and the lead screw dri ve fromz the vicinity of the grinding wheel W, so-that they are much less liable. to injury from flying abrasive.

, urthermore, this off-set: construction permits me to use the separate shaft 55 a'n-dto form asatisfactory: driving. connection betweenfsaid shaft 55 and the leadscrew I am! also able to aceompl ishithis-wi thout limitingft-he travel of the wheeli'table, as wou lld be the caseif this construction wereembodied in a. machineinot having my? outwardly project ingb'racket; V g Furthermore, I have providedsa' constrnc tion by, which the leadscrew may be quickly and: eaas-ily remdved for repairs or replace ment, whenever this becon res necessary. In

aving loosened the several connections as abate descr ibedi l rotete the lead screw in its nut sufficiently to draw it out of the end of the shaft and Iam able to lift out the lead screw andfits bearing-bracket as a unit from the machine for making such adjustments or replacements as inlay be desired; all without removing the wheel table from the grinding machine- Tll'lS: 1s a very marked i-mprove-- ment over I any previous machine of which; I

have knowledg'e,in which previous machines.

it iscommonly necessary tosubstantiall-y' dismantle. the grinding machine inorder to re move the lead screw therefrom.-

Telescoping. guards90j and- 791. (Fig. 5) on the bracket LO-and wheel table 11- affordadditional protectionrforthe lead screw drive.

7 Ha-izingthus described my invention and the advantagesthereof, v Lido not wish to be l-imitedto the details herein disclosed otherwise than as set forthin' the claims,.but.what

Irclaimrisdep V 1. In a grinding machine, base, a wheel .tahle sliclable: thereon-,1 arl-ead' screw v for i said wheel table, a nut for; saidxlea'd' screw, a beari ngbradreti for saidnut, means-to detachably 1 secure said bracket on 'saiidiwheeltable; and

means for adjusting saidnut relativeitosaitd bracket andtois'ai'd. lead screw thereby toit'ake up Wear. '8

- In a; grinding; machine,: a. base, aewheel table slidablea thereox'r,w a lead; screw? for. said wheeltahlet a nut-for said: lead screw", a bearing bracket for said nut, and means to detachablysecure; said bracket on'said. wheel 'table,: 'sai-'d securing. means being mounted in ar'recess in; sai'd tablet and said: nut and lead a being. readily removable fromv said inachiheawhile sa'i d' :wheel slide remains mounted thereon. r i

3. In a "grindingfmachine, a'I-ba'se, a wheel table slidabi e' thereon, a leadscrew for said wheel table, a: nut for said lead screw, a bear ing bracket for said. nut, means to detac'hablyf secure said bracket on said wheel table;.:.said bearing. bracket having an up standing flange extending axially of said: lead screw, andisai d ta'ble ha ving an upright l'on gitadimellyextended bearing surface for enga ementby said flange, and havin'g-clamp devices to secure-said parts together; 4. In a grinding machine, a base, a driving sh aftj aflwheel table 'slidab'le on said base, a

l'ead screw thereformountect" in oifset rela' tionito saidd rivingshaft, and connections between said drivin slid/ft and said lead screw, said connections including a short shaft mounted in separate bearings aligned with said lead screw,and detachable connections between said short shaft and said lead screw. 1

5. The combination in a grinding machine as set forth in claim 4, in which said short shaft is provided with a flanged and recessed end, and said lead screw is provided with an extension centered in said recess, and with a collar adapted to be clamped against the flanged end of said short shaft.

6. The combination in a grinding machine as setforth in claim 4, in which said short shaft is provided with a flanged and recessed end, and said lead screw is provided with an extension centeredin said recess, and with a collar adapted to be clamped against the flanged end of said short shaft, and in which means is provided to prevent relative angular movement between said collar and flange. 1

7. In a grinding machine, a base, a driving shaft, a wheel table slidable on said base, a lead screw therefor mounted in offset relation to said driving shaft, and connections between said driving shaft and said lead screw,

said connections including .a short shaft mounted in separate bearings aligned with said lead screw, and detachable connections between said short shaft and said lead screw, said short shaft and said driving shaft connection being mounted on a separate frame member projecting outwardly from the end of said base.

8. In a grinding machine, a base, a wheel table slidable thereon, a lead screw for'said wheel slide, an outwardly projecting bracket fixed to the end of said base and having an opening aligned with said lead screw, a driving shaft mounted in offset relation to said lead screw, a-driving gear thereon, and driving connections between said driving gear and said lead screw, including a short shaft mounted in separate bearings and aligned with said lead screw, said driving connections being mounted on and supported by said bracket.

9. In a grinding machine, a base, a Wheel table slidable thereon, a lead screw for said wheel slide, an outwardly projecting bracket fixed to the end of said base and having an opening aligned with said lead screw, a driving shaft, a driving gear thereon, driving connections between said driving gear and said lead screw including a train of change gears, a supporting plate for said change gears centered in said bracket opening and wheel table, a split nut having a plurality angularly adjustable about the axis thereof, i

said plate being mounted on said bracket, and means to secure said plate in angularly adjusted position with said change gearsin operative relationto said driving gear.

10. In a grinding machine, a base,a wheel table slidable thereon, a lead screw for said 

